Host-VM Groups¶

Overview¶

Host-VM Groups define affinity and anti-affinity rules that control the placement of virtual machines on specific hosts within a cloud or cluster. These groups allow administrators to:

• Pin VMs to specific hosts (affinity)

• Prevent VMs from running on the same host (anti-affinity)

• Group hosts and VMs for licensing, compliance, or performance requirements

Host-VM Groups can be configured at the Cloud level or the Cluster (Server Group) level.

Role Requirements¶

• Infrastructure: Clouds or Infrastructure: Clusters role permission at Full or Group access is required to create, edit, or delete Host-VM Groups.

• Read access allows viewing Host-VM Groups only.

Viewing Host-VM Groups¶

From a Cloud:

1. Navigate to Infrastructure > Clouds

2. Click the name of a Cloud

3. Select the HOST-VM GROUPS tab

From a Cluster:

1. Navigate to Infrastructure > Clusters

2. Click the name of a Cluster

3. Select the HOST-VM GROUPS tab

The list displays all configured Host-VM Groups with their name, type, and member count.

Creating a Host-VM Group¶

1. Navigate to the Cloud or Cluster detail page

2. Select the HOST-VM GROUPS tab

3. Click + ADD

4. Configure the following fields:

   NAME

   A descriptive name for the group.

   TYPE

   The group type determines the placement behavior:

   • Affinity — VMs in this group should run on the specified hosts. Use for workloads that need to be co-located.

   • Anti-Affinity — VMs in this group should NOT run on the same host. Use for high-availability configurations.

   • Site Group — (Cluster-level only) Groups hosts and VMs by physical site for stretch clusters. Do not create Site Groups on a two-node GFS2 cluster; adding them switches the Distributed Worker witness to siteWitness. See Two-Node Clusters with a Witness and Stretch Clusters & Witness Nodes.

   RESOURCE POOL

   (Cloud-level groups) Select the resource pool that this group applies to.

   SERVERS

   Select the hosts (hypervisor servers) that are members of this group. Multiple hosts can be selected.

   TENANT PERMISSIONS

   Control which tenants can see and use this Host-VM Group:

   • Public — Visible to all tenants

   • Private — Visible only to selected tenants

5. Click SAVE CHANGES

Editing a Host-VM Group¶

1. Navigate to the Cloud or Cluster detail page

2. Select the HOST-VM GROUPS tab

3. Click the edit icon next to the group

4. Modify the desired fields (name, servers, permissions)

5. Click SAVE CHANGES

Deleting a Host-VM Group¶

1. Navigate to the Cloud or Cluster detail page

2. Select the HOST-VM GROUPS tab

3. Click the delete icon next to the group

4. Confirm the deletion in the prompt

Use Cases¶

High Availability

Create an anti-affinity group containing VMs that form an HA cluster (e.g., database replicas). This ensures they are placed on different hosts so that a single host failure does not take down all replicas.

Licensing Compliance

Create an affinity group to ensure VMs that require specific host-level licenses (e.g., Oracle, SQL Server) are placed only on properly licensed hosts.

Performance Isolation

Create affinity groups to co-locate VMs that frequently communicate with each other, reducing network latency.